1. Field of the Invention
The present invention relates generally to engine lubrication systems, and particularly to devices for connecting an external oil cooler to an engine lubrication circuit, whereby the lubricating oil is kept reasonably cool under high load conditions.
2. Prior Art
My U.S. Pat. No. 4,335,688 discloses an internally partitioned manifold adapted to be interposed between an engine and an oil filter. The manifold has threaded openings for operatively mounting external oil line connecting to an external oil cooler. Oil can thus flow from the engine through the cooler and filter, and then back into the engine for recirculation through the engine to perform its lubricating action.
The manifold disclosed in U.S. Pat. No. 4,335,688 is clamped to the engine by a special connector which has a cylindrical section extending through the manifold. The cylindrical section is internally threaded for connection with an externally threaded hollow boss extending from one face of the engine. An hexagonal enlargement on the connector defines a shoulder which acts as a clamp to securely hold the manifold on the engine. The special connector further includes an externally threaded tubular section that serves as mounting means for a spin-on oil filter.
My U.S. Pat. No. 4,278,275 discloses an adapter having an internal hollow boss which is internally threaded for threaded connection with an externally threaded boss on an engine, whereby the adapted can be screwed down against an annular engine surface. Two passageways through the adapter provide for the circulation of engine oil through an external cooler. The adapter has two concentric O-ring grooves therein for sealing engagement with the engine surface. Either one (or both) of the O-ring grooves may be used for sealing purposes, depending upon variations in engine surface dimension.
Other manifolds have been developed for direct connection to a hollow engine boss, without using the above-described special connector. These other manifolds have integral internally threaded central walls, whereby the manifold can be turned bodily about the axis of the mounting boss on the engine in order to mount the manifold on the engine. Such manifolds may have provisions thereon for mounting a spin-on oil filter.
Different engines have differently dimensioned hollow mounting bosses, which can relate to the outside diameter of the mounting boss or the thread configuration. Sometimes the differences relate to the measurement system used in engine manufacture, e.g., English measurement or metric measurement. The differences may relate to the thread pitch, i.e., the threads per inch. The boss differences make it somewhat difficult to design a universal manifold construction, i.e., a manifold that will fit all or most engines.